Connecting piece and battery

Abstract

The invention provides a connecting piece and a battery. The connecting piece is used for connecting a pole and a tab of the battery and comprises a pole connecting part, a tab connecting part and a fusing part, and the fusing part is connected with the pole connecting part and the tab connecting part and protrudes in the direction away from the pole; the fusing part is provided with a first surface and a second surface which are arranged away from each other, the first surface is located on one side, close to the pole, of the fusing part, and the first surface and the second surface are covered with insulating glue layers. The fusing structure in the connecting sheet provided by the invention can be rapidly fused when the pole group is short-circuited, and the risk of re-connection of the tabs and the connecting sheet is not caused; meanwhile, the boss type fusing structure can meet the design requirements that the overall structure of the connecting piece is simple and flat on the basis that the boss type fusing structure does not make contact with the pole column, the installation space of the pole lug is enlarged, and therefore the over-current capacity of the pole group is improved, and safe use of the pole group is guaranteed.

Description

Technical Field

[0001] The present application belongs to the technical field of power batteries, and specifically relates to a connecting piece and a battery. Background Art

[0002] The electrode stack of a lithium-ion battery primarily consists of a electrode stack cover, tabs, and a stack. Connectors connect the electrode stack cover and tabs to conduct the current from the stack to the electrode stack cover. Existing connectors typically incorporate a fuse mechanism that quickly opens in the event of a short circuit, immediately severing the connection between the electrode stack cover and the interior of the stack and preventing further violent reactions in the stack.

[0003] However, during the production of the electrode group, in order to avoid the fuse structure and the electrode column, the space of the electrode ear is often sacrificed, which greatly causes overcurrent problems and affects the safety performance of the electrode group.

[0004] How to improve the design of the connecting piece, optimize the internal structure of the pole group, and improve the safety performance of the pole group are the problems that need to be solved at present. Summary of the Invention

[0005] The present invention provides a connecting piece and a battery, aiming to solve the problems of a connecting piece in an existing battery having a complex structure and too small a design space for a terminal tab caused by preventing a fuse structure from contacting a terminal column.

[0006] On the one hand, an embodiment of the present application provides a connecting piece for connecting a battery post and a tab, comprising a post connecting portion, a tab connecting portion, and a fuse portion, wherein the fuse portion is connected to the post connecting portion and the tab connecting portion, respectively, and protrudes in a direction away from the post;

[0007] The fuse part has a first surface and a second surface that are arranged in opposite directions. The first surface is located on a side of the fuse part close to the pole. The first surface and the second surface are covered with an insulating rubber layer.

[0008] In some embodiments, there is a first dimension D1 mm between the first surface and the second surface;

[0009] At least one through hole is provided on the fuse portion, the through hole passes through the first surface and the second surface, and along the third direction, the through hole has a second size D2 mm;

[0010] Meets: D2≥1.5D1.

[0011] In some embodiments, along the first direction, the fuse portion has a third size D3 mm, and the through hole has a fourth size D4 mm;

[0012] Satisfies: D4≤D3.

[0013] In some embodiments, the fuse portion has a maximum cross-sectional area S mm in the thickness direction. 2 , satisfying: S = D1·(D7-nD2);

[0014] Wherein, D7 is the seventh dimension between two vertices of the fuse portion along the third direction, n is the number of the through holes, and (D7-nD2)≥4mm.

[0015] In some embodiments, the maximum cross-sectional area S further satisfies:

[0016] S = γC;

[0017] Wherein, C is the capacity of the electrode group, in Ah; γ is the area coefficient, which satisfies: 0.04mm 2 / Ah≤γ≤0.08mm 2 / Ah.

[0018] In some embodiments, the maximum cross-sectional area S further satisfies: 4≤S≤12.

[0019] In some embodiments, the third dimension D3 mm satisfies: D4+0.8≤D3≤D4+1.2.

[0020] In some embodiments, the fourth dimension D4 mm satisfies: D1≤D4≤2D1.

[0021] In some embodiments, along the third direction, the pole connecting portion has a fifth dimension D5 mm, satisfying: 1 / 3D5≤D2≤2 / 3D5.

[0022] In some embodiments, the first dimension D1 mm satisfies: 0.6≤D1≤1.2.

[0023] On the other hand, an embodiment of the present application provides a battery, comprising:

[0024] a housing, the housing comprising a receiving cavity;

[0025] a pole group, the pole group being located in the accommodating cavity;

[0026] A pole tab, the pole tab being located on the top of the pole group and connected to the pole group;

[0027] A cover plate, the cover plate is connected to the shell and covers the accommodating cavity, the cover plate includes a pole; and a connecting piece in any of the above embodiments, wherein the pole connecting portion is connected to the pole, and the tab connecting portion is connected to the tab.

[0028] In some embodiments, a sixth dimension D5 mm is defined between the first surface and the pole along the second direction;

[0029] Satisfies: 2≤D6≤4.

[0030] The present application provides a connecting piece for connecting a battery pole and a lug, comprising a pole connecting portion, a lug connecting portion, and a fuse portion. The fuse portion is connected to the pole connecting portion and the lug connecting portion, respectively, and protrudes away from the pole. The fuse portion has a first surface and a second surface disposed in opposite directions, the first surface being located on a side of the fuse portion closer to the pole, and the first and second surfaces being covered with an insulating adhesive layer. The fuse structure in the connecting piece provided by the present application can quickly fuse when a pole group short circuits, without causing the risk of the lug and the connecting piece being reconnected. At the same time, the boss-type fuse structure can achieve the design requirements of a simple and relatively flat overall structure of the connecting piece while ensuring that it does not contact the pole, thereby expanding the installation space of the lug, thereby improving the current capacity of the pole group and ensuring the safe use of the pole group. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0032] Figure 1 A schematic structural diagram of a connecting piece provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of a top view of a connecting piece provided in an embodiment of the present application;

[0034] Figure 3 A schematic diagram of a top view of a connecting piece provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of a partially enlarged structure of a connecting piece provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of a top view of a connecting piece provided in an embodiment of the present application;

[0037] Figure 6 A schematic structural diagram of a battery provided in an embodiment of the present application;

[0038] Figure 7 A bottom-view structural diagram of a battery cover provided in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of an assembly of an electrode group and a connecting piece provided in an embodiment of the present application;

[0040] Figure 9 A schematic structural diagram of a battery cover provided in an embodiment of the present application;

[0041] Figure 10A partially enlarged structural diagram of a battery cover provided in an embodiment of the present application;

[0042] Figure 11 A schematic structural diagram of a connecting piece provided in another embodiment of the present application;

[0043] Figure 12 A schematic top view of the structure of a connecting piece provided in another embodiment of the present application.

[0044] 10-pole connection part, 20-ear connection part, 30-fuse part, 31-first surface, 32-second surface, 33-through hole, 40-insulating rubber layer, 100-housing, 200-pole group, 300-cover plate, 301-pole, 400-ear. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly specified and specifically limited. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0047] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0048] See also Figures 1 to 3The first embodiment of the present application provides a connecting piece for connecting a battery pole 301 and a tab 201, comprising a pole connecting portion 10, a tab connecting portion 20, and a fuse portion 30. The fuse portion 30 is connected to the pole connecting portion 10 and the tab connecting portion 20, respectively, and protrudes in a direction away from the pole.

[0049] The fuse portion 30 has a first surface 31 and a second surface 32 that are disposed opposite to each other. The first surface 31 is located on a side of the fuse portion 30 close to the pole. The first surface 31 and the second surface 32 are covered with an insulating rubber layer 40 .

[0050] The boss-type fuse structure can achieve the design requirements of a simple and relatively flat overall structure of the connecting piece while ensuring that there is no contact with the pole, thereby expanding the installation space of the pole ear, thereby improving the current capacity of the pole group 200 and ensuring the safe use of the pole group 200.

[0051] See also Figure 4 In some embodiments, there is a first dimension D1 mm between the first surface 31 and the second surface 32;

[0052] At least one through hole 33 is provided on the fuse portion 30, and the through hole 33 passes through the first surface 31 and the second surface 32, and along the third direction Z, the through hole 33 has a second size D2 mm;

[0053] Meets: D2≥1.5D1.

[0054] By controlling the thickness of the through hole (ie D1) and the width in the third direction Z (ie D2) to satisfy the above relationship, the processing and forming of the fuse part 30 can be facilitated, and defects such as stamping deformation, notches, and burrs caused by an excessively small width-to-thickness ratio can be avoided.

[0055] In some embodiments, the first dimension D1 mm satisfies the following: 0.6 ≤ D1 ≤ 1.2. It is understood that the value of the first dimension D1 (unit: mm) can be any value among 0.6, 0.8, 1.0, 1.2, or a range between any two values. When the first dimension D1 mm satisfies the above value range, it can ensure that the fuse 30 can be melted in time when thermal runaway occurs, while ensuring the overall strength of the fuse 30 so that it does not vibrate and deform, thereby causing damage to the electrode group.

[0056] In some embodiments, along the first direction X, the fuse portion 30 has a third dimension D3 mm, and the through hole 33 has a fourth dimension D4 mm;

[0057] The condition D4≤D3 is satisfied to ensure that the fuse part 30 completely covers the area where the through hole 33 is located in the first direction X, so that when thermal runaway occurs, the pole connection part 10 and the tab connection part 20 can be completely melted to ensure the safety of the pole group 200.

[0058] In some embodiments, the fuse portion 30 has a maximum cross-sectional area S mm in the thickness direction. 2 , satisfying: S = D1·(D7-nD2);

[0059] D7 is the seventh dimension of the fuse portion 30 between two vertices along the third direction Z, n is the number of through holes 33 , (D7−nD2)≥4 mm, and n is preferably 1-2.

[0060] When n=1, the through hole 33 can be set at the center position of the fuse part 30, and the distances between the two ends of the through hole 33 in the third direction Z and the two vertices of the fuse part 30 in the third direction Z are respectively greater than or equal to 2 mm, which can prevent the fuse part 30 from melting prematurely when current passes through, thereby helping to improve the safety of the battery.

[0061] In some embodiments, the maximum cross-sectional area S further satisfies:

[0062] S = γC;

[0063] Where C is the capacity of the electrode group, in Ah; γ is the area coefficient, which satisfies: 0.04mm 2 / Ah≤γ≤0.08mm 2 / Ah.

[0064] It is understandable that the value of the area coefficient γ (unit: mm 2 / Ah) can be any value among 0.04, 0.05, 0.06, 0.07, 0.08 or a range between any two values. When γ satisfies the above value range, the maximum cross-sectional area 30 of the fuse 30 and the capacity of the electrode group 200 can form an ideal adaptation relationship.

[0065] Based on the above embodiment, the maximum cross-sectional area S further satisfies: 4≤S≤12. It can be understood that the value of the maximum cross-sectional area S (unit: mm 2 ) can be any value among 4, 6, 8, 10, 12 or a range between any two values.

[0066] The requirements for the maximum cross-sectional area S of the fuse 30 will vary for different battery electrode group capacities. During electrode group use, the larger the capacity, the greater the current passing through the fuse during a short circuit. Large overcurrent and a small cross-sectional area will lead to accelerated heating and premature melting. Small overcurrent and a large cross-sectional area will prevent the fuse from melting in time during a short circuit. Therefore, the higher the battery capacity, the larger the maximum cross-sectional area S of the fuse 30 required. Further, Table 1 shows the optimal maximum cross-sectional area S of the fuse 30 for electrode groups of different capacities.

[0067] Table 1

[0068] Capacity(Ah) ＜90 90～130 131～160 ＞160 <![CDATA[S(mm 2 )]]> 4-5 5-7 8～10 12 and above

[0069] See also Figure 5 In some embodiments, the third dimension D3 mm satisfies the following: D4 + 0.8 ≤ D3 ≤ D4 + 1.2. When the third dimension D3 mm and the fourth dimension D4 mm meet these conditions, a safe space can be maintained between the fuse 30 and the terminal 301 even after the insulating adhesive layer 40 is applied.

[0070] In some embodiments, the fourth dimension D4 mm satisfies: D1≤D4≤2D1.

[0071] See also Figure 5 In some embodiments, along the third direction Z, the terminal connection portion has a fifth dimension D5 mm, satisfying the following relationship: 1 / 3D5 ≤ D2 ≤ 2 / 3D5. When the two satisfy this relationship, the structural strength of the cross-section of the fuse portion 30 can be ensured, preventing the connection piece from breaking and failing under mechanical impact.

[0072] See also Figures 6-7 A second embodiment of the present application includes a battery, comprising:

[0073] The housing 100 includes a receiving cavity;

[0074] The electrode group 200 is located in the accommodation cavity;

[0075] The electrode tab 400 is located on the top of the electrode group 200 and is connected to the electrode group 200;

[0076] The cover plate 300 is connected to the housing 100 and covers the accommodating cavity. The cover plate 300 includes a pole 301 and a connecting piece in any of the above embodiments.

[0077] See also Figures 7-8 The connecting piece is provided between the housing 100 and the pole group 200 , wherein the pole connecting portion 10 of the connecting piece is connected to the pole 302 , and the tab connecting portion 20 is connected to the tab 201 .

[0078] See also Figure 9 The connecting piece can be connected to the pole 302 by welding.

[0079] See also Figure 10 In some embodiments, a sixth dimension D6 mm is formed between the first surface 31 and the pole 301 along the second direction Y;

[0080] Satisfies: 2≤D6≤4. It can be understood that the value of the sixth dimension D6 (unit: mm) can be any value among 2, 2.5, 3, 3.5, 4, or a range between any two values.

[0081] In other embodiments of the present application, the structure of the connecting piece can also be a step structure with one side raised, such as Figure 11-12 As shown, in the battery, the pole connecting portion 10 of the connecting piece is connected to the pole 302 , and a certain distance is formed between the tab connecting portion 20 and the tab 201 .

[0082] The battery provided in this application is described below with reference to specific embodiments:

[0083] Example 1

[0084] This embodiment provides a connecting piece, such as Figures 1 to 3 As shown, it includes a pole connecting portion 10, a tab connecting portion 20 and a fuse portion 30. The fuse portion 30 is connected to the pole connecting portion 10 and the tab connecting portion 20 respectively, and protrudes in a direction away from the pole;

[0085] The fuse portion 30 has a first surface 31 and a second surface 32 that are disposed opposite to each other. The first surface 31 is located on a side of the fuse portion 30 close to the pole. The first surface 31 and the second surface 32 are covered with an insulating rubber layer 40 .

[0086] See also Figures 4-5 , wherein a first dimension D1=0.8 mm is present between the first surface 31 and the second surface 32;

[0087] At least one through hole 33 is provided on the fuse portion 30 , and the through hole 33 passes through the first surface 31 and the second surface 32 . Along the third direction Z, the through hole 33 has a second size D2 = 4 mm;

[0088] Along the first direction X, the through hole 33 has a fourth dimension D4=1.5 mm;

[0089] The maximum cross-sectional area S of the fuse portion 30 in the thickness direction is 1.5 mm. 2 .

[0090] This embodiment also provides a battery based on the above-mentioned connecting piece structure, such as Figures 6-8 As shown, including:

[0091] The housing 100 includes a receiving cavity;

[0092] The electrode group 200 is located in the accommodating cavity and includes a pole ear 201;

[0093] The cover plate 300 is connected to the housing 100 and covers the accommodating cavity 101. The cover plate 300 includes a pole 301; and a connecting piece in any of the above embodiments, wherein the pole connecting portion 10 is connected to the pole 302, and the tab connecting portion 20 is connected to the tab 201.

[0094] A sixth dimension D6=2 mm is formed between the first surface 31 and the pole 301 along the second direction Y;

[0095] Examples 2 to 7

[0096] The electrode and battery structures of Examples 2 to 7 are consistent with those of Example 1, with only structural parameters being adjusted.

[0097] Comparative Examples 1 to 6

[0098] The electrode and battery structures of Comparative Examples 1 to 6 are consistent with those of Example 1, with only the structural parameters being adjusted.

[0099] The relevant parameters of Examples 1 to 7 and Comparative Examples 1 to 6 are shown in Table 1.

[0100] Table 1

[0101]

[0102]

[0103] For the battery electrode group vibration and short circuit tests in Examples 1 to 7 and Comparative Examples 1 to 6, the test method refers to GB38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles", including the following steps:

[0104] When the electrode group is fully charged, the external resistance is less than 5mΩ. Perform a short-circuit test to observe the heat spread of the electrode group and detect the temperature rise inside the electrode group.

[0105] Mechanical shock: The shock waveform is 7g, a half-sine waveform of 6ms, and the axial direction is the Z direction; the number of shocks is 6 times in both positive and negative directions; the interval between two adjacent shocks is not less than 5 times the shock pulse duration.

[0106] Battery pack vibration: Sine wave sweep frequency, 7-18Hz: 10m / s2; 18-30Hz: from 10m / s 2 Gradually reduce to 2m / s 2 , 30-50Hz: 2m / s 2 Single scan 15min, total 12 scans, 3h.

[0107] The test results are shown in Table 2.

[0108] Table 2

[0109]

[0110]

[0111] As can be seen from Table 2, the connecting piece provided by the present application and the battery with the connecting piece have good safety performance in different size ranges. They can quickly melt when the electrode group is short-circuited without causing the risk of the tab and the connecting piece being reconnected; at the same time, the tab space can be increased, the overcurrent capacity of the electrode group can be improved, and the safe use of the electrode group can be ensured. According to Comparative Example 1, it can be seen that when the maximum cross-sectional area S exceeds the upper limit, it does not melt in time during the short-circuit test; in Comparative Example 2, because D1 exceeds the lower limit, the bending deformation of the fuse part 30 area is serious, the connecting piece bends downward seriously, and the electrode group has overlapped; in Comparative Example 3, the maximum cross-sectional area S exceeds the upper limit and does not melt in time during the short-circuit test; in Comparative Example 4, because D6 exceeds the lower limit, after the fuse part 30 melts during the short-circuit test, the connecting piece rises and overlaps with the cover plate pole, forming a short circuit again, and the battery cell heat spread test fails. In Comparative Examples 5 and 6, because the maximum cross-sectional area S exceeds the lower limit, the fuse 30 blows prematurely when the temperature rise inside the battery cell is not obvious during the short-circuit test. There is still a lot of room for the battery cell to go out of control, and the battery cell is over-protected.

[0112] The above is a detailed introduction to a connecting piece and a battery provided in the embodiments of the present application. Specific examples are used in this application to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A connecting piece for connecting a pole and a pole ear of a battery, characterized in that: It comprises a pole connecting portion, a pole lug connecting portion and a fuse portion, wherein the fuse portion is respectively connected to the pole connecting portion and the pole lug connecting portion and protrudes in a direction away from the pole; The fuse part has a first surface and a second surface which are arranged in opposite directions. The first surface is located at a side of the fuse part close to the pole. The first surface and the second surface are covered with an insulating glue layer.

2. A connecting sheet according to claim 1, characterized in that: There is a first dimension D1 mm between the first surface and the second surface; At least one through hole is provided on the fuse portion, the through hole passes through the first surface and the second surface, and along the third direction, the through hole has a second size D2 mm; Satisfies: D2≥1.5D1.

3. A connecting sheet according to claim 2, characterized in that: Along the first direction, the fuse portion has a third size D3 mm, and the through hole has a fourth size D4 mm; Satisfies: D4≤D3.

4. A connecting sheet according to claim 3, characterized in that: The fuse portion has a maximum cross-sectional area S mm in the thickness direction. 2 , satisfying: S = D1·(D7-nD2); Wherein, D7 is the seventh dimension between two vertices of the fuse portion along the third direction, n is the number of the through holes, and (D7-nD2)≥4mm.

5. A connecting sheet according to claim 4, characterized in that: The maximum cross-sectional area S further satisfies: S = γC; Wherein, C is the capacity of the electrode group, in Ah; γ is the area coefficient, satisfying: 0.04mm 2 / Ah≤γ≤0.08mm 2 / Ah.

6. A connecting sheet according to claim 3, characterized in that: The maximum cross-sectional area S further satisfies: 4≤S≤12.

7. A connecting sheet according to claim 3, characterized in that: The third dimension D3 mm satisfies: D4+0.8≤D3≤D4+1.2; and / or, The fourth dimension D4 mm satisfies: D1≤D4≤2D1.

8. A connecting sheet according to claim 2, characterized in that: Along the third direction, the pole connecting portion has a fifth dimension D5 mm, satisfying: 1 / 3D5≤D2≤2 / 3D5; and / or, The first dimension D1 mm satisfies: 0.6≤D1≤1.

2.

9. A battery, characterized in that: include: A housing, wherein the housing comprises a receiving cavity; A pole group, the pole group is located in the accommodating cavity; A pole lug, the pole lug is located on the top of the pole group and connected to the pole group; a cover plate, the cover plate being connected to the housing and covering the accommodating cavity, the cover plate comprising a pole; and The connecting piece according to any one of claims 1 to 8, wherein the pole connecting portion is connected to the pole, and the tab connecting portion is connected to the tab.

10. A battery according to claim 1, characterized in that: A sixth dimension D6 mm is formed between the first surface and the pole along the second direction; Satisfies: 2≤D6≤4.

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